Quinolinium salts of pamoic acid



' Edward Finest... and Dkinaid F. waatgst-ci,

have properties which restrict their use in pharmaceutical l ated witlirthein'se iof'the 'simple'pyrvinium salts are'their i ea e abs bu 1 State;

' pretest-14o)? I'The presentiiuventicmis -concerned with quinol ininm l6 salts of pamoic acid-,1with. methods for theirmanufacture,

' andwith their employment in therapeutic applications.

gMo're particularly, the present inventionrelates tQsa-lts comprising the -6-dimethylamino2 [2-(2,5-dimethyl-1- phenyl-3 pyrryDvinylLl-methylquinolinium cation (also known as the pyrvinium cation) 7 a andan anion'o'f pampie aaqgwmcn 1 23: ydro'xy- 7 1,1-dinaphthylmethane-3;3'-dicarboxylic acid 'Pyrvinium chloride, accompound described in .Enample 7-of'U.S. Patentv2,515',912,;andother simple pyrvinium salts," are therapeutically .useful as anthelmintieagents. They. are eflectivesagainst. parasitic nematodes, including nematodes of-the genera -Enterobiusg(0xyuris)' andv Stronglyloides. Such simple:pyrvinium@ salts, however,

applications. They have an intensely bitter taste, and 5 because-of the high incidence of 1 pinworm infestations in young children, for whom capsules-..and;eoatedtablets are often impractical dosage form's,'-the simple pyrviniumsalts, such :as' the chloride, are unsatisfactory. for "use. in; a high proportion of cases. Qther disadvantages associtendency to produce nausea their staining --properties' and the side-efiects which theyproduce." felf. i

It is "an object ofathes present ainventionq'to provide 4 pyrvinium salts of high anthelmintic? activity, whichzsalts' are notably free of the; disagreeable, taste, tendency to. I

produce nausea, staining properties, and side-reactionsof l i i' fc li S io l p y 1 1; i fother desirable'results are'achieved p s h:pYr i m t a d a'cidl j'Sal ts f this cdnstitution are e aa sf 719 at rnsoli b yl evenge? greatly minimize'permanent staiu L In additi ni -theyare essentially tasteless, so that they m be-formulated -into suspensions which are pharma .ceutically' acceptable for oral administration; Such='pa-:' a

"The reaction product s 2,925,417 Patented Feb. 16, I

moatesalts exhibit a high specificity of action in the treatment of helminthiases and are markedly tree of undesirable side efiects;

Representativecompounds of this invention are pyrviniumpamoate, wher 'ein= both of the- 'carboxyl groups of pamoic acid partierpatie-in thesaltvformation, and pyryin; I v yyhe'r'einonlytoneof the carbonyl H groupsfqf par'noic; 'acid participates in salt .formation..

ium-acid pamoa The former compound is preferably madQby treating" appr x mate-1 c molecular equivalents; or formula weights of a soluble pyrvinium salt withfll molecularequivalent or formula weight'of a soluble salt of pamoic acid which is formed by neutralizationz ofboth of the carboxyl groups with a base. ;The same compound can be obtained when the ;same reactants are employed-in:

different ratios. Pyrviniumacid pamoate isfpreferably;

madev by treating 1 molecular equivalentofa soluble' pyrvinium salt 'with 1 molecular equivalentl of a solub1e.

aeidsalt of pamoic acid, or with a reagent such as one 7 comprising a disodium saltaof pamoicwacid andran, equimolar quantity-pf a-mineralqacid; The termisoluble salt is ,used herein-inQa-relative sense, and means, a' degree of solubility:substantially greater than that ex- I hibit d byjpryvinium pamoate or pyrvinium acidpamo ate. Thus, sodium acid pamoate is a soluble salt by this definitiomalthough' it may actually appear as an insoluble phase in a particular reaction mixture.

:Because pamoic acid is a tetrabasic acid containingtwophenolie groupsas well as two carboxyl groups; the

use ofsuchbamoate saltsas the'trisodiumfsalt .and the tetrasodiummalt makes possible the formation of insolublepyr-yinium salts of pamoieacid having more than 2,

molecular equivalents of the pyrvinium cation for each molecular equivalent of a pamoate anion. Such salts are also within the scope of this invention. a

-Pyrvi 'um salts of ,pamoic acid can also be made by the direct interaction of pamoic acid and a soluble pyrvinium salt -in a neutral solvent.

,-Reactants'-suitable for carrying out the process of this invention can be selected from among pyrvinium chloride, bromide,:iodide, perchlorate, thiocyanate, acetate, methylsulfate, benzenesulfonate, p-toluenesulfonate and other, soluble pyrvinium salts;. and from among sodium pamoate potassium pamoate, ammonium pamoate, magnesium pamoate, simple amine salts of pamoic acid, corresponding acid salts such as sodium acid pamoate,

reagents comprising pamoic acid and'suflicient base to neutralize one or more. ofthe 'acidiegroups, other reagents comprising a soluble 'salt ofpamoic'acid and,

pamoic acidv itself. Inthis disclosure aterm such as sodium: pamoate, not otherwise qualified, designatesthe i disodium salt.

Suitable, reaction mediain which to carry outthesalt.

7 formation are solvents in which the reactants are at;

least partially so1uble,;and which arerelatively unr'e- "activel toward each ,of,the .r eactants.' Reaction media.

preferr'e' dbeeause of satisfactory solvent properties, u'n- 1 w 'andTineXpensiveness are AWaterIand aque alkanols,..although other satisfactory mediafcan'b lec'tedfrQm among a'wide variety of s olvents ,".,'pa

larly' thb's e which areneutral napalm; The-salt .fori;

mation proceeds immediately upon admixture of'th'e reactants, although in manyfca'sles' .a high yield and'a crystalline form,co nducive to rapid filtration are facilil tated' by heating-the react'ion mixture for up toabout an' h'our' jandr then chilling it.

centrifug ation, or by filtration following-concentration of the reaction'mixture o'r dilution witha non-polar solvent or with water. j r

' The pyrvinium parrioate and py'rvinium' acid. pamoate of this invention are compou'ndsfiwhich retain the-highisolated a direct mtranen er activity of simple pyrvinium salts against nematodes,

but which are essentially tasteless and which exhibit each of the desirable properties described elsewhere in this disclosure. ,For these reasons they are particularly suitable for use in such dosage forms asr s uspensions and uncoated tablets This invention will appear more fully from the examples which follow, wherein are'illustratedvarious of the procedural modifications which can-be successfully employed inthe practice of this invention. The scope of th e'invention is not limited thereby, as'many modifi cations in rnaterials and methods will beap parent from thisdisclosurelto those skilled in the art.

Example 1 V A hot, ;filtered, water solution containing- 12.2 g. of pyrvinium chloride dihydrate is added slowly with vigorous stirring to a solution of--6.0 g. of sodium .pamoate monohydrate in hot water. Whilestirring is continued,

the-resulting red suspension is heated. at about 90-100":

C. for-1 hour. The'insoluble product is collected on afilter and washed well with hot water. This compound is pyrvinium pamoate (a salt comprising 2 molecular equivalents of the pyrvinium cation to 1 molecular equivalent of the pamoate anion). The preparation obtained is commonly hydrated, although the anhydrous mate-' rial is"re adily obtained bydrying -for up to 30 hours at about 75 C. in a vacuum. This compound melts over a range from about 200 C.. and exhibits absorption maxirna at about 236, 356 and503 millimicrons.

By the foregoing procedure, with the substitution of 13.2 g. of pyrvinium iodide for the'pyrvinium chloride dihydrate, and with the substitution of an aqueous solution of 5.0 g. of pamoic acid and -1.45 g. of potassium hydroxide for the aqueous solution of sodium pamoate monohydrate, the same pyrvinium pamoate is obtained.

Example 2 .Example 3 A solution of2;25.g. of sodium pamoate monoh ydrate in 5 ml. of;hot water is added slowly, with stirring, to a l 1ot,' filtered solution of 2.27 .g. of pyrvinium chloride dihydrate in 250 mLof water. The precipitate which forms is collected directly on a filter, washed with hot water, and dried at 75 C. in avacuum. It is pyrvinium pamoate, substantially identical with the products of Examples 1 andjZ. I

The same pyrvinium pamoate is obtained by thesubstitution'of 218 g. of pyrvinium p-toluenesulfonate (prepared from --dimethylaminoquinaldine metho-p-toluenesulfonate and 2,5-dimethyl-1-phenyl-3-pyrrolecarboxaldehyde accordingto the process of U.S. Patent 2,515,912) forx'the pyrvinium, chloride dihydrate in. the foregoing procedure.

Ex mp e 4 .fiydroehlq iic: acid (somi, 0.1-N) is added to-a hot, filte ed..;so ut e q .Z-2 -.;g- .Qf py i i shlq dih drate in 250ml. ofwater. The,resulting solution is hen-addectshwlv. withtst rring. 'tosa u ionl f: 2255s- ..m-.. .amoatewnron hydrateM1250 of; water- Aftsril az ix ure i leated for iminut t abo t-9 100 (2., the insoluble product is eollecte on a filter, washedw tb. hotywat ra d d ied. :atxa ou 7: n; a

after prior softening from about 205 C.. and is pyrvinium acid pamoate (a salt comprising 1 molecular equivalent of the pyrvinium cation to 1 molecular equivalent of the acid pamoate anio'n).

Example 5 Hydrochloric acid (50 m1.,"o; 1 N) is added slowly to a solution of 227 g. of sodium pamoate monohydrate in 50 mllof water. 'The resulting'su'spens'ion is added, with stirring, to asolution of 2.25 got pyrvinium chloride dihydrate iii 250' ml. of hot Water. The'deep red, insoluble product is collected on a filter, washed with hot water. and dried for 1-6hours at about]? in a vacuum. This compound, isnpyry'inium acid pamoate,

Example 7- Hydrochloric acid (50 ml., 0.1 N) is added to a'solution of 2.27 g. of sodium .pamoatel monohydrate in 50 ml. of water. To.;the resultingsuspnsion is added a solution of 2.25 gJ'ofpyrvinium chloride dihydrate in 250 ml. of hot water. The insoluble red product is collected on a filter, washed with hot water and dried. It is pyrv niumsas ramn e sub ti l id n {with the products of ;Exampl es 4, 5 aud l v Example 8 Pyrvinium chloride (499.4 g., analyzing for 3.7% water and 96.3% pyrvinium chloride by difference) is dissolved in a mixture of 920 rrilfof water and 3680 ml. of ethanol by heating to about 60 C. with mechanical stirring. The hot solution is filtered and the filtrate is combined with washingsrtotaling 230 ml. of water and 920 ml. of ethanol. To it is added, with continuous stirring over a period .of .30. minutes, a filtered solution of 259.1 g. of sodium pamoate monohydrate in 3300 ml. of water.' .Stirring is continued fol-1:30. minutes mpre, and the v.mixtureis then cooledl'afid. refrigerated for/completeseparationof product. Themed productjis collected on. afiIter, washed with'. cold aqueousdethanol'. and dried. ItJis pyrviniumkpamo'atai substantially identical .withlthe productsfof i Examples':1;-2;and};

l v E m e 1. 11 A hot,'filtered solution of chlob ut salt of pamo 1 Q-.-,- mtair a roximat p' sa ismi vsa master ind;

by nitrogen analy sis alscule v u valsi ts.921 1 slam pl a substantially identical with gthe product of Example 4.

Example 11 A solution of 1.12 g. of sodium pamoate'monohydrate in 100 ml. of water is filtered into a solution of 8.5 ml.

of concentrated hydrochloric acid in50 ml. of water,

and the precipitated pamoic acid iscollected ona filter,

' washed with hot water, and'dissolved in 6.0 mlg-of pyridine. .The pyridine solution (which contains a pyridine salt "of pamoic acid) .is clarified byfiltration and added to a hot,aqu eous solution of. 2.27 g.'-of'pyrvinium chlo ride. The red, insolublefproduct'is collected on a filter, v I washed with hot-water and dried. "It is'pyrvin'ium pamoate, substantially identical with the products of Ex 9. Example 12 A solution of 0.97 g. of pamoic acid in 200 ml. of boiling propylene glycol is added to a hot, stirred solution of 2.27 g. of pyrvinium chloride dihydrate'in 50 ml. of propylene glycol. The resulting suspension is allowed to cool to about 90 '95 C., diluted with 250 ml. of hot water, and filtered. The product collected is a red pyrvinium salt of pamoicacid.

amples 1, 2, 3, 8 and Example 13 a A solution of 0.97 g. of pamoic acid-in 50 ml.. of hot dimethylformamide is added slowly to a hotQstirr'ed solution of 2.09 g. .of pyrvinium chloride in 50 of What is claimed is: I 1. 6 dimethylamino 2 [2 I ly-3-pyrryl vinyl]-l methylquinolinium 'salt. of 2,2'-dihya droXy-l,1'-dinaphthylmethanc-3,3i-dicarboxylic acid.

2.. 6 dimethylamino 2 [2} 2,5 dimcthyl-l-phen yl-3-pyrryl)vinyl]-1-methylquinolinium salt with one-half formula weight of 2,2-dihydroxy-1,lfedinaphthylmeth-' ane-.3,3-dicarboxylic acid anion.

boxylic acid and soluble salts thereof and isolating the, resulting product.

hot dimethylfo'rmamide. The resulting solution is cooled to about 100 C. and diluted with 120 ml.'.of hot water. The mixture is heated for an additional '5' minutes at about 100 C. and then filtered. The product collected is a red pyrvinium salt of pamoic acid. I

"Eirample 14 A pharmaceutically-acceptable suspension "of pyrvinium pamoate for oral administration isprepared as follows:

List of ingredients:

Benzoic acid 9 V Propylene glycol ml 60 Carbowax 1000- monostearate g 6 Pyrvinium pamoate g 9 Water ml 500 Sucrose g 300 Methyl cellulose (25 centipoises) g 7 Imitation strawberry flavor. ml-.. 0.12

Water to make 1000 ml.

solution results. The solution is slowly poured, into about 500 ml. of water under vigorous stirring,gproducing a suspension of pyrvinium pamoate. This suspension is diluted immediately with the sucrose-methyl cellulose solution. Flavor is added, and the final volume is brought to 1000 ml. with'water;

The Carbowax 1000 monostearate is ester of a polyethylene glycol havingan average molecular weight of aboutl000. It is satisfactory to substitute for this material another higher fatty acid ester of a I polyethylene glycol of comparable molecular weight. It is also satisfactory to substitute pyrvinium acid vol. 68, pp. 1841-1842(1946).

pamoate for the pyrvinium pamoate.

the monostearoyl -dihydroxy-1,1'-dinaphthylmethane-3,3'-dicarboxylic acid anion which comprises: mixing 6-dimethylamino-2-[2-' carboxylic acidanionr a i 4. A process for' the manufacture "of. a 6-dimethyl- 3' ,amino-Z-[2-(2,5-dirnethyl-1- phcuyl 3 pyrryl)viny1]- I,

l-methylquinolinium salt of 2,2'-dihydroxy.-1,1-dinaph thylmethane-3,3'-dicarboxylic acid which comprises: mix- 3 6 dimethylaminoQ-i2-(2,5-dimethyl 1 phe'nyl-3-Ji y pyrryl)vinyl] l-methylquinolinium saltfwith' one formula weight of 2,2 '-dihydroxy-1,1'.dinaphthylmethane-3, 3'-di ing a ysoluble "6-dimethylamino-2-[2-(2,5-dimethyl-1- phenyl-3-pyrryl)vinyl']-l-methylquinolinium salt in an unreactive medium with a member of the ;class consisting of 2,2-dihydroxy-1,l'-dinaphthylmethane-3,3'-dicar- 5. A process for the manufacture of a o-dimethylamino-2-[2 (2,5-dirnethyl l phenyl 3 pyrryl-)vinyl] i l-m'et hylquinolinium salt of 2,2'-dihydroxy-1,1-dinaphthylmethane-3,3'-dicarboxylic acid which comprises: mix ing a soluble 6-dimethylamino-2-[2-(2,5-dimethyl-1-phenyl-3-pyrryl)vinyll-l-methylquinolinium salt in an unreactive mediumwith a soluble salt of 2,2-dihydroxy-1,1- dinaphthylmethane-3,3 '-dicarboxylic acid and isolating the insoluble reaction-product.

6. A process for the manufacture of a G-dimethylamino-2-l2-(2,5-dimethyl 1 phenyl 3 pyrryl)vinyl]- l-methylquinolinium salt of 2,2'-dihydroxy-1,1-dinaph-- thylmethane-3,3-dicarboxylic acid which comprises: mixing a 6-'dimethylamino-2-[2-(2,5-dimethyl 1 phenyl-3- pyrryl)vinyl]-1-methylquinolinium halide with an alkali metal salt of 2,2'-dihydroxy-1,1-dinaphthylmethane-3,3- dicarboxylic acid in an aqueous solvent and isolating the insoluble reaction product.

7. A process for the manufacture of 6-dimethylamino- 2-[2-(2,5-dimethyl-l-phenyl 3 pyrryl)Vinyl]-l-methylquinolinium salt with one-half formula weight of 2,2'-dihydroxy 1,1' dinaphthylmethane-3,3'-dicarboXylic acid anion which comprises: mixing 6-dimethylamino-2[2-(2,5-

dimethyl-l-phcnyl 3 pyrryl)vinyl]-l-methylquinolinium chloride with alkali metal 2,2'-dihydroxy-1,1'-dinaphthylmethane-S,3'-dicarboxylate in an aqueous solvent and isolating the insoluble reaction product.

8. A process for the manufacture of 6-dimethylamino- 2-[2-(2,5-dimethyl-1-phenyl 3 pyrryl)vinyl]-1-mc.thylquinolinium salt with one-half formula weight of 2,2-

(2,5 dimethyl 1 phenyl 3 pyrryl)vinyl] -1-methylquinolinium chloride with sodium 2,2'-dihydroxy-1,l-dinaphthylmethane'-3,3f-dicarboxylate in an aqueous alkanol' and isolating the insoluble reaction product..

References Cited inthegfile ofthis patent UNITED STATESPATENTS 1,872,826

Schulemann et a1. Aug. 23, 1952: 2,515,905 Sprague et al. July 18, 1950 1 2,515,912 JVan Lare et a1. July 18,, 1950 2,715,622 5 Gerzon et'al. Aug.-l6, 1955 r OTHER REFERENCES Campbell: Ioumal'of the.' American Chemical Society,

2,5 dimethyl-l-pheni 

1. 6 -DIMETHYLAMINO - 2 - (2 - (2,5 - DIMETHYL-L-PHENLY-3-PYRRYL)VINYL)-1-METHYLQUINOLINIUM SALT OF 2,2''-DIHYDROXY-1,1''-DINAPHTHYLMETHANE-3,3'' DICARBOXYLIC ACID. 